The invention relates to an induced or selected jam in a machine, and, more particularly, to a programmed jam for training or diagnostics.
In using reproduction machines, there are various types of system shut downs or malfunctions that can occur in a variety of operating modes. Operator involvement in correcting malfunction such as document and paper jams can often be extensive particularly in machines with various accessories such as sorters, collators, finishers and document handlers. The problem of correcting the malfunction, maintaining the integrity of the run in process, and minimizing down time and operator involvement can be significant. Operator training and understanding of jam clearance and recovery procedures is extremely important in minimizing machine downtime. In addition, rapid and correct diagnosis of jam related malfunctions by a service representative is of paramount importance. An invaluable aid to a service representative is any technique to aid and simplify the procedure for pinpointing jam related malfunctions.
The prior art is replete with diagnostic techniques. For example, U.S. Pat. No. 4,206,995 to Legg, assigned to the same assignee as the present invention, discloses a system for moving documents in a document handler to preselected locations for inspection for proper document alignment. U.S. Pat. No. 4,335,949 to Kukucka et. al. also assigned to the same assignee as the present invention, discloses a system for successively displaying data related to the travel of documents in a document handler between sensors.
Various techniques of jam clearance exist in the prior art. For example, U.S. Pat. No. 4,627,711 to Schron, assigned to the same assignee as the present invention, discloses a control system for controlling the shutdown of a paper path system in a copy machine when a paper handling fault occurs. Upon detecting a malfunction or jam, the control system evaluates the status of all sheets in a sheet handling system and makes determinations whether to hold sheets from entering into a boundary between two zones or to drive a sheet at a boundary into a next zone.
U.S. Pat. No. 4,231,567 to Ziehm, assigned to Xerox Corporation, discloses a method and apparatus for clearing jams in a transport path of a copier. Widen a jam is sensed, in-process sheets either at a jam location or at an area upstream of the jam location are clustered while sheets downstream from the jam location are allowed to continue out into a catch tray.
U.S. Pat. No. 4,786,041 to Acquaviva et al, assigned to the same assignee as the present invention, discloses a document handler jam clearance and job recovery system. Upon the occurrence of a paper jam, the system determines whether a document has jammed in a first, second or third document path jam zone and automatically provides a preliminary job recovery operation before the document handler is fully stopped.
A deficiency in these prior art devices is the lack of selective real time jam capability to assist in operator jam recovery training or to assist in jam diagnostics.
It is an object, therefore, of the present invention to be able to selectively jam the machine or position copy sheets for operator clearance. Another object of the present invention is to be able to program various jams in a machine's paper path and document handler to illustrate proper jam clearance techniques by actual removal of a jammed sheet. Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.